Numerous studies established personality traits as predictors of career success. However, if and how career success can also trigger changes in personality has not received much attention. Drawing from the neosocioanalytic model of personality and its social investment and corresponsive principles, this paper investigated how the attainment of objective career success contributes to personality change in the Big Five traits of neuroticism, extraversion, openness, agreeableness, and conscientiousness. We conducted cross-lagged analyses with three measurement waves over eight years with a representative sample of 4′767 working adults from the German Socio-Economic Panel and examined if objective success (i.e., income and occupational prestige) predicted changes in personality. We also tested if effects differed across age groups or between men and women. Results showed that career success predicted changes in personality for neuroticism, extraversion, and openness. Higher income predicted a decrease in neuroticism and increase in openness. Higher prestige predicted a decrease in extraversion and an increase in openness. Results did not differ according to age group or for men or women. We discuss the results in light of the effects that career success can exert on personality development and the complexity inherent in observing personality change.